Controlled degradation and crosslinking of polypropylene induced by gamma radiation and acetylene |
| |
Authors: | Adriana Yoshiga Harumi Otaguro Duclerc Fernandes Parra Luís Filipe C P Lima Ademar B Lugao |
| |
Affiliation: | 1.Instituto de Pesquisas Energéticas e Nucleares IPEN/CNEN,S?o Paulo,Brazil |
| |
Abstract: | Isotactic polypropylene (iPP) undergoes crosslinking and extensive main chain scissions when submitted to irradiation. The
simultaneous irradiation of PP and acetylene is able to control chain scission and produce grafting. The grafted PP further
reacts with PP radicals resulting in branching and crosslinking. In this work, commercial polypropylenes (iPP) of different
molecular weights were irradiated with a 60Co source at dose of 12.5 kGy in the presence of acetylene in order to promote the crosslinking. The mechanical and rheological
tests showed a significant increase in melt strength and drawability of the modified samples obtained from resins with high
melt flow index. The characterization of the molecular modifications induced by gamma irradiation of isotactic polypropylenes
under acetylene atmosphere proved the existence of branching, crosslinking and chain scission in a qualitative way. The G′ and G″ indicated the presence of LCB in all samples. Therefore, PP irradiation under acetylene was proved to be an effective approach
to achieve high melt strength polypropylene (HMSPP). |
| |
Keywords: | Melt strength Drawability iPP Acetylene Gamma irradiation |
本文献已被 SpringerLink 等数据库收录! |